The invention concerns a process for the manufacture of printed products such as books, booklets or the like by printing on webs of paper or plastic, in accordance with a predetermined sequence of pages for a printed product, as well as the crosswise or the crosswise and lengthwise cutting of the web into individual sheets, such that they can be processed further.
Such a process particularly concerns the printing of books and booklets in smaller series.
A digital printing system for the processing of sheets, which becomes uneconomical for editions exceeding more than approximately 500 copies, and the offset printing process, used for printing editions of approximately 2500 copies and more, leaves a gap for a more economical production with a digital printing system starting with webs.
A known digital printing system by the company NIPSON Printing Systems GmbH, exhibited during the DRUPA' 95, at Dusseldorf (Germany) which is suitable for the initially described process, can print on a paper web with a maximum speed of 60 m/minute, so that a capacity of one hundred bound books per hour is possible. A cutting device and a book binding machine in this order are installed downstream of the printing system. Further processing options are known to include folding, stacking, wire-stitching, etc.
Digital printing systems belong to the group of printing systems where paper is printed on or processed in a predetermined page sequence.
The known processing of a web from a roll of paper does not permit a production with variable formats during a continuous processing path. That is to say the specific format size of an end product respectively depends on the width of the web that is used, or the web width must correspond to the format of the printed product that is produced.
To obtain a format variety, offset processing uses folding devices which do not permit a continuous processing to the end product. Above all, this concerns a folding device that requires different exits, or discharge areas, when processing printed products that are folded in different ways. A folding device with several discharge areas is not suitable for economical processing because this would require an additional high technical expenditure in order to transport all processed products to a joint delivery location from which they can be processed further. This is particularly true for an on-line processing of webs printed on with a predetermined page sequence.